Transcript

Listener Tony [Skura] of Nome, Alaska, asked: What’s an itch and can you take a picture of one? We turned to physiologist David Andrew of the University of Sheffield in England. He says when something irritates your skin, your immune system responds with a chemical called histamine. It can make your skin turn red and swell, and it also sends signals to the itch centers of your brain. As for taking a picture:

DAVID ANDREW (University of Sheffield):
We can put people in scanners, like MRI scanners and PET scanners, and take a photograph of their brain in action. So we can see an itch in a sort of indirect way either by listening to neurons talk to each other or by looking at patterns of neurons in the human brain.

HIRSHON:
If you’re itching to ask a science question, just call us at 1-800-why-isit. If we use it on the air, you’ll win a Science Update mug. I’m Bob Hirshon, for AAAS, the science society.